Rodney

Another good substitute for after run oil is Rislone (in the yellow container). Any air tool oil works well also. Do not use WD40 for long term storage. If you use it for cleanup or anything, rinse it out well with a good oil. Never use it in an older engine unless you want to agravate the wear as, any rust already present will be turned into a nice abraisive compound to accelerate the wear of the engine the next time you use it. While Marvel Mystery Oil is better than nothing, not by much. The Marvel Mystery Air Tool oil is good. On a 4 stroke, running the engine dry at the end of the day does little or no good. You have to get the gunk out of the lower crankcase and the only way to flush that out is to put at least a teaspoon full of after run oil into the crankcase breather hole and then turn the engine over by hand a few times while it is in various positions to completely coat the bearings down there. Even in the two strokes, you need more than a few drops to do any good.